MOSCOW (Reuters) – One of President Vladimir Putin’s top allies said on Sunday she saw no logic in deploying U.N. peacekeepers along the border between Russia and Ukraine, something Kiev and Washington favor.

Putin this month suggested armed U.N. peacekeepers be deployed to eastern Ukraine to help protect ceasefire monitors from the Organization for Security and Cooperation in Europe (OSCE) and to help end a conflict between Ukrainian troops and Russia-backed separatists, which has killed more than 10,000 people since 2014.

German Chancellor Angela Merkel has called the proposal “interesting,” while Kurt Volker, the U.S. envoy to Ukraine peace talks, says the suggestion gives negotiators more ideas with which to seek a resolution to the conflict.

But differences about where the peacekeepers would operate risk sinking the plan.

Putin originally said the peacekeepers could be deployed along the line of contact between Ukrainian government forces and pro-Russian separatists, but later said they could also be deployed in other areas where OSCE inspectors work.

Washington and Kiev also want peacekeepers to be deployed along those parts of Ukraine’s border with Russia which Kiev does not control.

However, Valentina Matviyenko, speaker of the Russian upper house of parliament and a close Putin ally, said on Sunday Moscow strongly objected to that idea.

“I don’t see any logic in such a proposal,” Matviyenko, visiting Turkmenistan, told reporters, the Interfax news agency reported.

“Those who would like to surround the residents of the self-proclaimed republics of Donbass (Donetsk) and Luhansk with barbed wire or to simply destroy these people … will not succeed.”